Abstract

Electron-transfer processes play a vital role in many biological phenomena, from energy storage to photosynthesis. The labelled
electron method using positive muons allows such transfer processes in macromolecules, such as proteins, to be probed on a microscopic
level. Here we present the results of an experiment using the labelled electron method with mSR to investigate electron-transfer processes
in apoferritin. The data is well described using the Risch–Kehr model and the results suggest one dimensional, or intra-chain diffusion
occurs in this system. Intra-chain diffusion rates of 1012 rad/s have been determined.